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SAI INTERNATIONAL SCHOOL

Class VII

Sub: Mathematics

Chapter- 11: Area and Perimeter

Worksheet-1(Answer)

1. b) 14 sq cm
Area of triangle = ½ × base × height
= ½ x 7 x 4
= 14cm 2
2. (b) 13 cm
We know that, area of triangle = ½ × base × height

30 = ½ × 5 cm × height

Height = (30 × 2)/5
Height = 60/5

Height = 12 cm

By the rule of Pythagoras theorem,
2
2
2
Hypotenuse = height + base
2
2
2
Hypotenuse = 12 + 5
2
Hypotenuse = 144 + 25 = 169
Hypotenuse = √169 = 13 cm
3. 10cm

4. Base of parallelogram = 20 cm
Height of parallelogram =?

2
Area of the parallelogram = 246 cm
Then,
Area of parallelogram = base × height

246 = 20 × height

Height = 246/20
Height = 12.3 cm

∴Height of the parallelogram is 12.3 cm.

5. Perimeter of square park = 96m = 4 x side of the square park